This document discusses contraindications for magnetic resonance imaging (MRI). It notes that MRI systems use strong magnetic fields, pulsed gradient magnetic fields, and pulsed radiofrequency fields which can pose risks if certain metallic or electronic implants are present in the body. The document lists many common contraindications such as pacemakers, aneurysm clips, cochlear implants, and metallic foreign bodies. It also discusses safety considerations for oxygen supply in the MRI suite and identifies some implant materials that are usually MRI compatible like titanium, aluminum, and brass.

1. PRESENTED BY
MUHAMMED SWALI HM
BSc RADIOLOGY FINAL YEAR
GANGA INSTITUTE OF HEALTHSCIENCES
COIMBATORE

2. • Magnetic resonance imaging (MRI) is a
method that has evolved continuously during
the past 20 years, yielding MR systems with
stronger static magnetic fields, faster and
stronger gradient magnetic fields, and more
powerful radiofrequency transmission coils
• To evaluate the contraindications to MRI is
equivalent to understanding the safety issues
surrounding the use MRI.

3. Risks associated with MRI may be attributed to one or to a
combination of the three main mechanisms of the system
Strong static magnetic fields
As a result of ferromagnetic interactions, an object or device
may be moved, rotated, dislodged, or accelerated toward the
magnet. The ‘‘projectile effect’’ means that, depending on the
type of magnet and the intensity of the generated field, to
varying extent, objects are attracted to the centre of the
magnet
For example, helium or oxygen cylinders, ventilators,
wheelchair, etc),

4. Pulsed gradient magnetic fields
• Gradients are time-varying magnetic fields used to encode
for various aspects of the image acquisition. They are much
weaker than the main magnetic field. As they are repeatedly
and rapidly
• turned on and off the rapid changing magnetic fields can
induce electrical currents in electrically conductive devices
and may directly cause neuromuscular stimulation.

5. Pulsed radiofrequency fields
• The main biological effects of radiofrequency fields is their
thermogenic effect. Some of the applied energy will be
absorbed by the body and converted into heat.
• Radiofrequency energy can also induce electrical currents in
wires and leads which might induce arrhythmias.

6. The following conditions are often contraindications to MRI scanning.
Implanted pacemaker or
defibrillator:
Until recently, MRI was
contraindicated for all patients with
implantable cardiac devices
because the fields generated have
the potential to damage
components and interfere with
functioning. New MRI-conditional
pacemakers are now available, but
MRI for patients with even these
new devices should be undertaken
only when deemed medically
necessary and under strict
guidelines

7. Ferromagnetic aneurysm clips
May move or become dislodged under the
force of the magnetic field
A cochlear implant
It can be damaged or create tissue damage in the
presence of an MRI system.
Metallic foreign bodies
Shrapnel or other metallic objects in the body can be
heated and/or moved by the magnetic field. This includes
any minute metal chips or fragments that may have
lodged in the eye as a result of welding, grinding, or any
type of accident

8. Some varieties of ocular implants
It pose a risk of damage to the eye due to
metallic components. A Swan-Ganz catheter
may malfunction during MRI scanning.
Prosthetic heart valves:
Although prosthetic heart valves and
annuloplasty rings are made from a variety
of materials, numerous studies have
demonstrated that MRI examinations are
safe

9. • Tattoos and Cosmetics
• Claustrophobia
• Permanent Contraceptive Devices
• Aneurysm clip(s)
• Any metallic fragment or foreign body
• Coronary and peripheral artery stents
• Aortic stent graft
• Prosthetic heart valves and annuloplasty rings
• Cardiac occluder devices
• Vena cava filters and embolisation coils
• pregnancy or breast feeding

10. • Haemodynamic monitoring and temporary pacing devices,
Eg, Swan–Ganz catheter
• Haemodynamic support devices
• Cardiac pacemaker
• Implanted cardioverter-defibrillator (ICD)
• Retained transvenous pacemaker and defibrillator leads
• Electronic implant or device, eg, insulin pump or other infusion
pump
• Permanent contraceptive devices, diaphragm, or pessary
• Cochlear, otologic, or other ear implant
• Neurostimulation system
• Shunt (spinal or intraventricular)

11. • Vascular access port and/or catheter
• Tissue expander (eg, breast)
• Joint replacement (eg, hip, knee, etc)
• Any type of prosthesis (eg, eye, penile, etc)
• Body piercing jewellery
• Hearing aid
• Renal insufficiency Known/possible

13. • MRI COMPATIBLE METALS ARE.
titanium Aluminum Brass

14. Usually MRI compatible
Cardiac
• Sternal wires
• Heart valves &
annuloplasty rings
• Coronary stents
• Epicardial wires (cut
short and taped)
• Other vascular stents,
coils and filters
Other
• Orthopaedic implants
• Contraceptive devices
• Dental implants

15. OXYGEN SUPPLY IN MRI SUITE
• Two types of Supply
1- Pipe Line Supply Branch From Central Oxygen Supply
Usually Mounted on the wall of the MRI Room
(Should Be MR Compatiable

16. 2- Cylinder Supply
Cylinder made up of Aluminum
Uses MR Compatible Oxygen regulator
Oxygen supplying mask have a metallic-
hook usually MR compatible